A modern and efficient variant of fuel injection technology used in modern two-stroke and four-stroke gasoline engines is Gasoline Direct Injection (GDI), sometime referred to as “Petrol Direct Injection”, “Direct Petrol Injection”, “Spark Ignited Direct Injection” (SIDI) or “Fuel Stratified Injection” (FSI), depending on the geography. In GDI engines, the gasoline is highly pressurized and is injected via a common rail fuel line directly into the combustion chamber of each cylinder, as opposed to conventional multi-point fuel injection that happens in the intake tract, or cylinder port.
GDI engines are prevalent in consumer vehicles and in commercial car and truck fleets because of the advantages associated with the GDI technology. For example, GDI engines exhibit increased fuel efficiency and high power output as compared to standard fuel injection engines, such as port fuel injection (“PFI”) engines. Emissions levels may also be more accurately controlled with the GDI system. In addition, there are minimal throttling losses in some GDI engines, when compared to a conventional fuel-injected or carbureted engine, which greatly improves efficiency and reduces ‘pumping losses’ in engines without a throttle plate.
However, although direct injection technology is reported to provide several advantages it is plagued with a significant drawback. Carbon build-up occurs in the intake valves that, over time, reduces the airflow to the cylinders, and therefore reduces power. In the conventional standard fuel injection or PFI engines, these deposits were removed by the fuel (often containing detergents) cleaning the surfaces of the valves as it was introduced into the combustion chamber. Because GDI engines inject the fuel directly into the combustion chamber, this cleaning effect is no longer performed. The build-up of the intake valve deposits may produce performance problems including decreased power and torque, lower fuel economy, higher emissions, starting issues, hesitation, pinging and rough idle. Additionally, small amounts of dirt from intake air may also attach to the intake walls. It has been reported that this build-up can result in break off that can travel downstream in the system and potentially result in catastrophic damage, such as holes in catalytic converters or sporadic ignition failures.
Currently the only effective methods available to clean these deposits is time consuming and expensive. The most effective ways involve disassembling the engine, removing the intake valves and blasting the deposits away by using walnut shells or other abrasives or by introducing straight solvents into the air intake system by specialized attachments performed by a licensed mechanic. Both of these methods are time consuming and come with a significant cost to the consumer.
A prior art attempt to develop resource efficient cleaning method was made by Wynnoil in the UK (sold under the name “Direct Injection Power”). The Wynnoil product used an aerosol device that was intended to deliver a cleaning formula of rapidly evaporating solvents to the intake surfaces. However, the Wynnoil product proved ineffective for several reasons relating to the structure of the dispenser and the composition of the cleaning fluid.
Thus, there remains a need in the art for systems and methods of effectively cleaning intake valve surfaces in situ in a GDI engine that is cost and time effective, easily carried out by an average automobile consumer, thereby permitting enjoyment of the benefits of a GDI engine without the performance limiting and/or potentially dangerous disadvantages associated with deposit build up.